int receive;

void usart_str(char *s)
{
   while(*s){usart_write(*s++);}
}

void main()
{
    Usart_Init(9600);
    TRISB=0b00000011;
    
    while(1)
    {
        if(!portb.f0)
        {
            portb.f7=1;
            Usart_str("stop");
            delay_ms(200);
        }
        if (Usart_Data_Ready()) {receive = Usart_Read();}

        while(receive){usart_write(receive);receive=0;}
        
    }
}